The Norwegian Coastal Administration (NCA) has awarded a contract to Van Oord Norway AS for counter filling in the wreck area for the submarine U-864, outside the island of Fedje on the west coast of Norway.

The German submarine U-864 was sunk by the British submarine Venturer in 1945 while it was heading to Japan with different war load, i.e. 1,857 containers with mercury that were stored in the keel of the submarine. Due to the torpedo attack, the submarine U-864 was divided in to sections and sunk to a depth of 145m to 160m.

Intended to ensure seabed stability in the area, this operation must be conducted regardless of the main measure chosen to protect the environment against mercury pollution from the German World War Two wreck.

Stringent requirements have been set for environmental monitoring of the work. Such checks will be conducted during the maritime operations by the Norwegian Institute for Water Research (Niva) as a subcontractor to Van Oord.

“Following a detailed evaluation, Van Oord was found to have submitted the best overall tender,” says Johan Marius Ly, director of emergency preparedness at the NCA.

New geotechnical analyses of the seabed in the area around the Second World War wreck were conducted in 2013. On that basis, experts from the Norwegian Geotechnical Institute (NGI) and DNV GL recommended that counter filling should begin as soon as possible.

This operation involves laying some 100 000 cubic metres of sand and rock in order to stabilise the seabed.

“That in turn will reduce the risk of movement by unconsolidated sediments, including materials contaminated with mercury leaked from the submarine,” Ly concludes.

Established in the deepest part of the wreck area, the counter fill will not affect the choice of later measures to protect the environment.